If you want to know a lot about what was going on in Italy between 1450 and 1500, you’d be well advised to tackle a book that came out just this year. It’s entitled “The Borgias,” by G. J. Meyer, and is about the family that flourished in that half-century. The author is an American educated in this country who now lives in England.

The subtitle of the book is “The Hidden History,” which gives a hint that it does not follow where many other histories of that time and that family have gone. The chief difference is that the author makes a pretty good case that the stories of corruption and vice that have dominated accounts of the family members are to a large extent untrue, having been based on documents written by people who hated the Borgias for political reasons.

The Borgia family originated in Aragon when it was a separate country, not yet part of the country called Spain. By the middle of the fifteenth century the ruler of that country also was in possession of Sicily and the southern part of the Italian peninsula governed from the city of Naples and called the Kingdom of Naples.

On the Iberian peninsula the family spelled their name “Borja,” and Alonso de Borja became an advisor to the ruler of Aragon and went to Italy with him where he became a cardinal and eventually was elected pope, as Callixtus III. In that position he got a family member, Rodrigo Borgia, to come to Rome to take charge of a series of Vatican administrative tasks, becoming a cardinal in the process.

It is Rodrigo on whom the author concentrates his attention for a good share of the book. The man was tall, healthy, and of a nature that made him a good conversationalist and persuasive negotiator. He got along so well in the Vatican that he was kept in the administrative jobs by several successive popes. Finally, he himself was elected pope, taking the name Alexander VI.

The author is convinced that Rodrigo was not the sexual debauchee that he has often been accused of being. Those stories originated from people who either didn’t get what they wanted from him, or who had other reasons to blacken his reputation.

Since those days other circumstances have arisen that added to the problem. In Victorian times a definite anti-Catholic opinion arose, especially after the doctrine of papal infallibility was proposed. Although that doctrine is actually limited in scope, the anti-Catholic movement seized on it as indicative of something wrong with the religion.

The pope at the time the doctrine came into being was not the sort of person who could be accused of corruption or bad morals. So the researchers went back to study the records of previous popes. And there in the manuscripts were those accusations against Alexander VI. Biographers took it without checking it closely, the author of the present volume says, because of the prevailing sentiment against Catholic doctrine.

Reading the letters that Alexander wrote, biographers found him addressing Cesare Borgia as “my son.” That added to the feeling that Cesare and his sister Lucrezia were Alexander’s illegitimate children. But the present author points out that the pope used that term in addressing any male recipient. His messages to King Ferdinand of Spain also called him “my son.”

As far as Meyer is concerned, Cesare and Lucrezia were children of one of Alexander’s nieces and a husband who added the name Borgia to his own name after marriage. And he makes a pretty convincing case for that belief.

During that half-century Constantinople fell to the Turks, and the Turks began to expand into the Balkans and beyond. While concentrating on the Vatican and Italy the author includes some insight into what was happening on a wider scale. For instance, when a Venetian outpost in the eastern Mediterranean was overcome by the Turks, the Venetian commander surrendered on being promised that his head would not be severed from his torso. So instead they cut him in half at the waist.

Italy was far from a unified nation in those days. A series of city states and minor principalities made a complicated patchwork of the peninsula. And the ruling families were just as interconnected. In one aside, the author gives an example: “Lucrezia’s third marriage had made Cesare the brother of the bride of Elizabetta of Urbino’s brother Francesco Gonzaga’s wife’s brother Alfonso d’Este.” Diagrams are required to make such things understandable. Niccolo Machiavelli got along well with Cesare Borgia, despite the fact that as an envoy from Florence he feared that the Borgias had designs on Florence. But they both had a sense of satire and a quick wit.

This book gives you a good idea why Ferdinand of Spain was more interested in Italy than in the remote islands discovered far to the west by Columbus. Also why, as pope, Alexander VI gave Ferdinand and Isabella much more power over the Inquisition than was usual in most countries. In all, if you can thread your way among French intrigue, Spanish intrigue, Venetian schemes and Milanese aggressions, this is a very stimulating and rewarding volume.